From:   "Uladzislau Rezki (Sony)" <urezki@gmail.com>
To:     LKML <linux-kernel@vger.kernel.org>, RCU <rcu@vger.kernel.org>,
        "Paul E . McKenney" <paulmck@kernel.org>
Cc:     Michal Hocko <mhocko@suse.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Daniel Axtens <dja@axtens.net>,
        Frederic Weisbecker <frederic@kernel.org>,
        Neeraj Upadhyay <neeraju@codeaurora.org>,
        Joel Fernandes <joel@joelfernandes.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        "Theodore Y . Ts'o" <tytso@mit.edu>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Uladzislau Rezki <urezki@gmail.com>,
        Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>,
        Uladzislau Rezki <uladzislau.rezki@sony.com>,
        Trond Myklebust <trond.myklebust@hammerspace.com>
Subject: [PATCH 3/9] fs: nfs: sysfs: Switch to kvfree_rcu() API
Date:   Wed, 24 Nov 2021 12:03:02 +0100
Message-Id: <20211124110308.2053-4-urezki@gmail.com>
In-Reply-To: <20211124110308.2053-1-urezki@gmail.com>
References: <20211124110308.2053-1-urezki@gmail.com>
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From: Uladzislau Rezki <uladzislau.rezki@sony.com>

Instead of invoking a synchronize_rcu() to free a pointer
after a grace period we can directly make use of new API
that does the same but in more efficient way.

CC: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Uladzislau Rezki <uladzislau.rezki@sony.com>
---
 fs/nfs/sysfs.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/sysfs.c b/fs/nfs/sysfs.c
index 8cb70755e3c9..ff88d5d58e1e 100644
--- a/fs/nfs/sysfs.c
+++ b/fs/nfs/sysfs.c
@@ -113,10 +113,9 @@ static ssize_t nfs_netns_identifier_store(struct kobject *kobj,
 	if (!p)
 		return -ENOMEM;
 	old = rcu_dereference_protected(xchg(&c->identifier, (char __rcu *)p), 1);
-	if (old) {
-		synchronize_rcu();
-		kfree(old);
-	}
+	if (old)
+		kvfree_rcu(old);
+
 	return count;
 }
 
-- 
2.30.2